Bend Flexural Test
Bend Tests and Flexural Tests can be more complex than Tensile and Compression Tests.
Within the realm of flexural and bend testing applications, there are a wide variation of test methods that are used to characterize multiple materials properties, sample types, bend and flexural test fixtures, test calculations, and procedures.
For instance, customers use the terms ‘bend testing’ and ‘flexural testing’ interchangeably in describing test equipment requirements. Technically speaking, bend tests are different than flexural tests. Flexural tests tend to mimic tensile tests whereas bend tests most commonly refer to bending metal samples to determine ductility.
‘Bend tests’ suggest a test that makes the test sample bend but not break. ‘Flexure tests’, on the other hand, measure a test sample’s flexural modulus or flexural strength, amongst other measures.
Bend Flexural Test Machines
Bend flexural test machines typically are based on a universal test machine sized to test your range of test samples and equipped with flexural bend fixtures that match your test procedure.
Choosing the best test machine configuration consists of decisions regarding the load frame size and force capacity and controller attributes that match your budget or personal preferences. Note that all of our test controllers can perform a bend or flexural test.
Flexural Bend Test Fixtures
We offer an extensive modular product line of three and four point bend fixtures. A review of various test standards will reveal that each test standard tends to require different fixture configurations., several choices of three and four point bend fixtures are available. TestResources has almost 75 different fixtures that each satisfy different requirements of 50 common bend and flexure tests.
Bend test specimens are laid horizontally over a span consisting of two lower support anvils, with a force applied to the top of the material through a single upper point in the case of three point flexural bend tests. If the test procedure features two points of contact on the upper loading span, it is known as a four point flexural bend test. Our flexural bend fixtures can be configured for either three or four points or both (five point).
Flexural Calculations Produce Pata Similar to a Tensile Test
Once a flexural test sample fails, the maximum recorded force is converted to flexural strength of that particular sample. The goal of a bend test is not to load the material until failure but rather to bend the sample into a specific shape. In contrast, flexural tests typically break the test sample.
The biggest difference between a flexure test and a bend test is in the type of material being tested and the specific test information required.
Flexure tests measure the bend strength of a relatively brittle material. Bend tests measure the crack resistance of a ductile material. Bend tests apply forces that cause the sample to deform in a way that highlights imperfections in the test material for the purpose of determining the materials ductility. In contrast, a flexure test requires the test sample to be loaded until the sample completely ruptures allowing for the determination of the samples maximum flexural strength.
Do these differences really matter? They matter because they result in a variety of test results that are not the same. Call our flexural bend test application engineer and share what test expectations you have.
Planning to perform a flexure test?
Unlike a compression test or tensile test, a flexure test does not measure fundamental material properties. When a specimen is placed under flexural loading all three fundamental stresses are present: tensile, compressive and shear and so the flexural properties are the result of the combined effect of all three stresses as well as the geometry of the specimen and the rate the load is applied.
The most common purpose of a flexure test is to measure flexural strength and flexural modulus. ‘Flexural strength’ is the maximum stress at the outermost fiber on either the compression or tension side of the specimen. Flexural modulus is calculated from the slope of the stress vs. strain deflection curve. These two values can be used to evaluate the sample materials ability to withstand flexure or bending forces.
Three and Four Point Bend Flexure Tests
The two most common types of flexure test are three point and four point flexure bending tests. A three point bend test consists of the sample placed horizontally upon two points and the force applied to the top of the sample through a single point so that the sample is bent in the shape of a “V”. A four point bend test is roughly the same except that instead of the force applied through a single point on top it is applied through two points so that the sample experiences contact at four different points and is bent more in the shape of a “U”. The three point flexure test is ideal for the testing of a specific location of the sample, whereas, the four point flexure test is more suited towards the testing of a large section of the sample, which highlights the defects of the sample better than a 3-point bending test.
A bend test is similar to a flexure test in the type of hardware and test procedure involved. Bend tests are used with ductile materials whereas flexural tests are used with brittle materials.